Equivalent 4-node Enhanced Assumed Strain and hybrid stress shell elements in 6-parameter theory

摘要

We discuss the equivalence of semi-Enhanced Assumed Strain (EAS) and semi-hybrid stress (SEM) shell finite elements. We use the general nonlinear 6-field shell theory with kinematics composed of generalized displacements composed of the translation field and the rotation field. Due to the presence of rotation tensor the elements have naturally six nodal engineering degrees of freedom. We propose interpolation for a strain field and then we construct corresponding interpolation for a stress field. The key point of the present formulation is the asymmetry of membrane strain and stress field and application of EAS and SEM approach not only to minimize membrane locking but also for shear locking.